Lighting fixture



May 12, 1970 R. G. BLAISDELL ET AL 3,511,984

LIGHTING FIXTURE Filed Dec. 27, 196'? 2 Sheets-Sheet 1 .ri/ fl l c J FIG. I

INVENTORS RONALD G. BLAISDELL HENDRIK A. J. de VOS TTORN Y y 1970 I R. G. BLAISDELL ETAL 3,511,984

' LIGHTING FIXTURE Filed Dec. 27, 1967 2 Sheet S -Sheet 2 d/d'v/Y 2/ H i E i l U I 2 4 I I I4 FIG. 2

INVENTORS RONALD G. BLAISDELL HENDRIK A. J. de V S BY ATTORNEY United States Patent U.S. Cl. 24044.1 4 Claims ABSTRACT OF THE DISCLOSURE A luminaire for lamps of the metal vapor type in which an adapter ring may be interposed between the housing and the spider as a means for adjusting the relative location of the light center of the lamp with respect to the reflector whereby different light distribution patterns are obtained.

This invention re ates to luminaires and more particularly to lighting fixtures employing high pressure electric gaseous discharge devices, such as metal vapor lamps for example, as the light source.

Luminaires with these light sources are quite expensive as compared to incandescent light sources for example because they require a certain amount of auxiliary equipment for their operation. Further expense is incurred, requiring the purchase of a new luminaire, each time a customer wants to obtain a different light distribution pattern.

In view of the foregoing, the principal object of this invention is to increase the versatility of a luminaire for lamps of the metal vapor type without a significant increase in cost.

This and other objects, advantages and features are attained, in accordance with the principles of this invention by providing a simple means of shifting the relative location of the reflector with respect to the light source in a plane parallel to the longitudinal axis of the light source whereby a different light distribution pattern is obtained.

In the accompanying drawing, FIG. 1 is a front elevational view partly in section of a luminaire embodying the principles of this invention.

FIG. 2 is a fragmentary detail on an enlarged scale of the luminaire of FIG. 1, showing particularly the means employed for varying the relative location of the reflector with respect to the light source.

Referring now to the drawings, the luminaire illustrated therein comprises a housing 2 for the auxiliary electrical equipment normally associated with high pressure electric gaseous discharge devices of the metal vapor type, a lamp socket 4 secured to and depending from the bottom of the housing 2, a lamp 6 seated in the socket 4 and a reflector 8 within which the lamp 6 is disposed. The reflector 8 seats in a reflector support ring 10 with a gasket 12 disposed therebetween. The ring 10 is secured to a spider 14 which is attached to and depends from the bottom of the housing 2 and is concentric with the lamp socket 4. The reflector 8 is secured to the spider 14 by latches 16.

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As shown in FIG. 1, the top of the spider 14 is secured directly to and fits snugly against the bottom of the housing 2. When so located, the light source or lamp occupies a certain relative location with respect to the reflector 8 and thus a certain light distribution pattern is obtained. On the other hand, if a different light distribution pattern is desired, an adapter ring 18 is located between the spider 14 and the housing 2 as shown in phantom in FIG. 2. By interposing the adapter ring 18 between the housing 2 and the spider 14, the reflector 8 is .displaced downwardly a distance substantially equal to the Width of the ring because the reflector 8 is attached to the spider 14 by latches 16. The extent of this displacement is illustrated by the showing in phantom in FIG. 1 of the new locus of the peripheral lower edge of the reflector 8. Since the position of the lamp socket 4 has not changed, this displacement of the reflector 8 effects a change in the relative location of the reflector with respect to the light source and thus provides a different light distribution pattern. It will be readily apparent to those skilled in the art that other adapter rings of different lengths may be employed to obtain other light distribution patterns without departing from the spirit of this invention.

What we claim is:

1. A luminaire comprising:

a housing;

a lamp socket secured to and depending from said housing;

a spider secured to and depending from said housing and concentric with said lamp socket;

a reflector secured to said spider;

a lamp seated in said socket and located within said and means for adjusting the relative location of the light center of the lamp with respect to the reflector whereby different light distribution patterns are obtained.

2. The combination of claim 1 in which said adjusting means effects a displacement of the reflector with respect to the lamp.

3. The combination of claim 1 in which said adjusting means is interposed between said housing and said reflector.

4. The combination of claim 1 in which said adjusting means is an adapter ring interposed between said housing and said spider.

References Cited UNITED STATES PATENTS 3,284,624 11/1966 Brasty et a1. 24011.4

FOREIGN PATENTS 240,772 6/1960 Australia. 279,688 10/1914 Germany.

NORTON ANSHER, Primary Examiner R. P. GREINER, Assistant Examiner U.S. Cl. X.R. 240-114, 78 

